A server virtualization technology is a key technology based on an infrastructure layer in cloud computing. Deployment of multiple virtual machines (virtual operating systems) on a single physical node is implemented by virtualizing a physical server, so that a resource utilization ratio of the physical server can be improved and the cost of using can be reduced. In a virtual cluster, such multiple physical machines are managed unifiedly; in this way, through a virtualization technology, physical resources are abstracted into a resource pool formed by various resources such as storage, computing, and a network, and a virtual machine applies for a resource according to requirements and is deployed in the cluster.
One important characteristic of the virtual cluster is dynamic resources scheduling (Dynamic Resources Scheduling, DRS) (an important characteristic which is established on the basis of live migration of the virtual machine): A cluster management system monitors resource utilization ratios of each physical machine and virtual machine at regular time, and according to resource distribution conditions, adjusts distribution of virtual machines on physical machines by utilizing live migration, so as to implement load balance and cluster integration in the cluster range, thereby improving resource usage efficiency of each host and at the same time ensuring that each host bears proper loads. In virtual cluster integration, resource requirements in the virtual cluster are continuously monitored. During a period of a low utilization ratio, a resource requirement of the cluster decreases, workloads are integrated into a few physical machines and a host of another unused physical machine is turned off to decrease power consumption of the cluster. During a period of a high utilization ratio, resource requirements of workloads increase, and the host which is turned off is online again to ensure that a service level is met. The virtual cluster integration brings the following values: a power consumption cost and a heat dissipation cost of a data center are reduced, and energy efficiency of the data center is managed automatically.
In the existing virtual cluster integration technology, the minimum number of physical machines is taken as an integration target to find a proper migration policy for the virtual machine. Cluster solutions of main virtualization vendors (VMware and Citrix) all include a related virtual cluster integration technology. Distributed power management (Distributed power management, DPM) of VMware completes its virtual cluster integration, where an unnecessary physical machine is powered off to achieve an effect of energy saving and emission reduction. Its main mechanism process is: When a load of the whole cluster is lower than a threshold value for a period of time, the DPM first determines the minimum number of physical machines according to resource distribution conditions, and then gives virtual machine migration (the virtual machine is enabled to migrate from a physical machine with light loads to a physical machine with heavy loads as far as possible) and physical machine power-off instructions according to distribution conditions of virtual machines of physical machines in a current cluster, and executes virtual machine migration according to the migration instruction given in the foregoing; and the physical machine from which virtual machines are all migrated is powered off, so as to achieve a purpose for saving energy. However, under the circumstance that currently the scale of the virtual cluster is expanded continuously, there may be many integration solutions which are determined according to the minimum number of physical machines, and in the prior art, an integration solution with a better energy saving effect cannot be selected from these integration solutions.